The upper edge of a flat O-shaped hole 231 for the latch bar 24 at the center of base fixing plate 23 is provided with a notch 232 so as to install an upper cover 22; a nut cylinder 211 is provided at a position nearby the rear end of base body 210 so as to lock the upper cover 22; or, alternatively, a pair of protuberances are provided correspondingly at the front end of cover body 220 of the upper cover 22 so as to be installed at the notch 232 of latch fixing plate 23 at the front end of base 21; a tap hole 222 is provided correspondingly at a position nearby the rear end of cover body 220 so as to dispose a screw 27 in the nut cylinder 211 on the base body 210 for locking each other.
Since the base body 210 of base 21 of long and short latches 2a, 2b of conventional door lock is integrally molded together with the latch fixing plate 23 and no xe2x80x9cretractable mechanismxe2x80x9d is designed to adjust the length of latch, some separate molds have to be made so as to make the latches and upper covers with different length and to install a latch opening/closing mechanism 25 and latch bar 24 between the base 21 and the upper cover 22 (as shown in FIG. 4 and 5), and after a decorative panel 26 in riveted in front of the latch fixing plate 23, the long latch 2a and the short latch 2b are respectively made for the consumers"" optional purchase and installation.
Because the long and short latches 2a, 2b with specific length have to be made for the conventional door lock latch and no retractable mechanism to adjust the length of long and short latches is provided, frequently the consumers buy the wrong door locks which cannot be installed, and for the manufacturers, they have to produce both long and short latches 2a, 2b with different length and increase a doubled stock in their warehouse.
For the convenience of consumers"" optional purchases without troubles of installation, and also for the convenience of manufacturers"" production to decrease one half of their warehouse stock, the present inventor particularly invented xe2x80x9can improved door lock latchxe2x80x9d through his research and development.
The primary object of the present invention is to offer an improved door lock latch which is characterized in convenient installation and use, without identifying long or short one while optional purchase, and even if in case of undesirable length while installation, all to do is to loosen the screw to xe2x80x9cpull longxe2x80x9d for elongation or xe2x80x9cpress inxe2x80x9d for contraction and then to lock it then the short latch becomes long one or the long latch becomes short one.
Another object of the present invention is to offer an improved door lock latch which is characterized in the convenience of manufacturers"" production without separately making both long and short latches, and only one length is made enough to adjust the length of these latches.